64-66 starter brace to block screw; GM #273867; What finish?

[Gary B.]

Gary

[Leif A.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Gary,
Quoting from the seventh edition of the '67 AIM...

"The top of the brace is secured to the block with a cadmium or zinc plated 1/2" hex head bolt and captured serrated washer."

'63 - '67 used the same brace.

[Gary B.]

[Leif A.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Leif,

The ‘67 AIM lists that screw as GM #3848408, so different from the 64-66 screw, GM #273867. Also, the earlier screw does not have a captured washer, so it’s a different screw. And maybe has a different finish?

But you did get me to consult the ‘66 JG (Yes, I should have done that before) which says the brace “is attached to the block with a cadmium or zinc plated 1/2” hex flange bolt head or hex bolt with captive star washer.” I assume the “or” in that that wording suggests two different types of bolts are possible. The captive star washer version is what the LIC repro is. But not what came on my ‘66. Nor what others, including Dave Luikkonen and Rich Pasqualone, have described. They describe a bolt that is the same as mine, with a flanged head, having a serrated underside as a locking mechanism; not the star-washer version.

Gary

Gary,
OK, now you've got me confused. I guess the important thing is you now have an answer to your original question as to the correct finish of the bolt.
Here's my confusion in your last post. In your first paragraph you state "the earlier screw does NOT have a captured washer" then you go on to quote the '66 JM which states "hex bolt WITH captive star washer"...so, which one is it. Seems both '66 and '67 state the same thing...bolt with captive star washer.

[Gary B.]

1) hex flange bolt head

2) hex bolt with captive star washer

[Joe L.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Leif,

My reading of the ‘66 JG suggests the description includes two possibilities for the bolt:

1) hex flange bolt head

2) hex bolt with captive star washer

What makes me think that is the descriptions of the bolt from Dave Luikkonen and Rich Pasqualone of a bolt with a hex flange head, but with no separate/captive washer, vs the description in the ‘67 JG of a bolt with a captive serrated (star) washer.

Gary

Gary------

For info, hex flange head bolts with serrated bearing surface are never used in conjunction with any type lockwasher, captured or not

[Gary B.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Joe,

Am I correct that GM 273867 was never available in service? So, no chance of finding an NOS example.

Gary

[Leif A.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Leif,

The ‘67 AIM lists that screw as GM #3848408, so different from the 64-66 screw, GM #273867. Also, the earlier screw does not have a captured washer, so it’s a different screw. And maybe has a different finish?

But you did get me to consult the ‘66 JG (Yes, I should have done that before) which says the brace “is attached to the block with a cadmium OR zinc plated 1/2” hex flange bolt head or hex bolt with captive star washer.” I assume the “or” in that that wording suggests two different types of bolts are possible. The captive star washer version is what the LIC repro is. But not what came on my ‘66. Nor what others, including Dave Luikkonen and Rich Pasqualone, have described. They describe a bolt that is the same as mine, with a flanged head, having a serrated underside as a locking mechanism; not the star-washer version.

Gary

Gary,
Here's my thought and I'm sticking with it. The reason the '66 JM has the word "or" in their description is that possibly late in '66 production there was a switch over to the bolt type used throughout the '67 model run. Therefore, both have been seen on '66 models and that's why both are mentioned (and, correct) for the '66 model year. Make sense?

[Gary B.]

[Joe L.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Joe,

Am I correct that GM 273867 was never available in service? So, no chance of finding an NOS example.

Gary

Gary------


GM #273867 was once available in SERVICE. It was discontinued in March, 1973 and replaced by GM #9416897. The latter was discontinued without supersession in November, 1979.

The 273867 was a flanged, serrated, hex head bolt of 5/16-18 X 1/2" and zinc plated. I cannot find a description or specs on the 9416897.

[Gary B.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Joe,

The 267867 should be 273867. But the key thing for me is you confirmed it is zinc.

Thanks,

Gary

[Joe L.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Joe,

The 267867 should be 273867. But the key thing for me is you confirmed it is zinc.

Thanks,

Gary

Gary-----

That's a typo on my part. I'll correct it.

[Gary B.]

Re: 64-66 starter brace to block screw; GM #273867; What finish?

Joe,

The 267867 should be 273867. But the key thing for me is you confirmed it is zinc.

Thanks,

Gary